Method and apparatus for producing absorbent sanitary articles, and relative absorbent sanitary product

ABSTRACT

A method and apparatus for producing absorbent sanitary articles including an absorbent body having two front oblique sides and two rear oblique sides, and two longitudinal elastic bands attached to the absorbent body along said oblique sides, where each of said elastic bands includes a front section and a rear section separated from each other by transverse cuts and joined together by refastenable closure formations.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Italian Patent Application No.102019000022323 filed Nov. 27, 2019. The disclosure of the aboveapplication is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a method and an apparatus for producingabsorbent sanitary articles.

The invention was developed with particular regard to producingabsorbent sanitary articles that can be worn as pants, such as theso-called training pants.

The invention specifically relates to producing absorbent sanitaryarticles of the openable and reclosable type.

The present invention relates, in particular, to a method and anapparatus for producing absorbent sanitary articles according to theso-called “Machine Direction” production technique.

DESCRIPTION OF THE PRIOR ART

The absorbent sanitary articles known as “training pants” are normallyformed by an absorbent body having an elongated shape along alongitudinal axis, and two transverse waistbands (a front waistband anda rear waistband) applied to opposite ends of the absorbent body on thesurface that faces, during use, towards the clothing. The transversewaistbands may be elasticized and can be fixed to each other permanentlyor by refastenable closure formations.

For producing absorbent sanitary articles composed of an absorbent bodyof elongated shape and two transverse waistbands, a production techniquecalled “Cross Direction” is normally used, which consists of forming twocontinuous elastic parallel sheets, forming the front and rearwaistbands, which advance in a machine direction and applying theabsorbent bodies transversally between the continuous sheets. Theabsorbent bodies oriented transversely with respect to the machinedirection are fixed at their opposite ends to the continuous sheetsforming the waistbands.

Document WO2000/047151 A1 describes a method for producing absorbentsanitary articles of the type named “training pants” according to theMachine Direction production technique. The method described in thisdocument envisages the formation of a continuous absorbent compositesheet that advances in a machine direction, in the direction of itslongitudinal axis. Two continuous elastic bands are overlapped onrespective longitudinal side edges of the continuous absorbent compositesheet. The continuous elastic bands are fixed to the continuousabsorbent composite sheet along oblique junction lines with a V-shapeopen outwards. The method involves cutting the continuous compositesheet and the elastic bands along cutting lines in the shape of a doubleY, so as to give rise to discrete absorbent sanitary articles eachconsisting of an absorbent body and two longitudinal elastic bands fixedat opposite ends of the absorbent body along oblique sides.

The solution known from WO2000/047151 provides absorbent sanitaryarticles which are permanently closed and shaped like pants. The methoddescribed in WO2000/047151 cannot be used in the case in whichrefastenable absorbent sanitary articles are required, which areincreasingly requested on the market by virtue of their greaterconvenience of use.

OBJECT AND SUMMARY OF THE INVENTION

The present invention aims to provide a method and an apparatus forproducing absorbent sanitary articles that overcome the problems of theprior art.

In particular, the present invention aims to provide a method and anapparatus for producing refastenable absorbent sanitary articlescomposed of an absorbent body with an elongated shape and two elasticwaistbands parallel to the longitudinal axis of the absorbent body.

According to the present invention, this object is achieved by a methodand by an apparatus having the characteristics forming the subject ofclaims 1 and 6.

According to another aspect, the present invention relates to anabsorbent sanitary article having the characteristics forming thesubject of claim 8.

The claims form an integral part of the disclosure provided here inrelation to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in detail with reference tothe attached drawings, given purely by way of non-limiting example,wherein:

FIG. 1 is a plan view of an absorbent sanitary article according to thepresent invention in an extended configuration,

FIG. 2 is a perspective view of the absorbent sanitary article of FIG. 1in a configuration of use,

FIG. 3 is a plan view of the absorbent sanitary article of FIGS. 1 and 2in an extended position and with the elastic bands open,

FIG. 4 is a schematic side view of a unit for producing elastic bands,

FIGS. 5-10 are schematic plan views illustrating various steps of amethod for producing elastic bands, corresponding to the positionsindicated by the arrows V-X of FIG. 4 ,

FIG. 11 is a schematic side view of a unit for applying elastic bandsonto a continuous composite web, and

FIGS. 12-17 are schematic plan views illustrating various steps of amethod for producing absorbent sanitary articles, corresponding to thepositions of the apparatus indicated by arrows XII-XVII of FIG. 11 .

It will be appreciated that the various figures may not be representedon the same scale. It will also be appreciated that some elements orcomponents have not been shown to simplify the understanding of thefigures.

DETAILED DESCRIPTION

With reference to FIGS. 1-3 , numeral 10 indicates an absorbent sanitaryarticle according to an embodiment of the present invention. Theabsorbent sanitary article 10 illustrated by way of example in FIG. 1represents refastenable training pants. However, it is understood thatthe present invention may also apply to absorbent sanitary articles ofanother type, for example, incontinence pads for adults.

The absorbent sanitary article 10 comprises an absorbent body 12 havingan elongated shape along a longitudinal axis A. The absorbent body 12has two longitudinal sides 14 that extend along a direction generallyparallel to the longitudinal axis A. The longitudinal sides 14 may bestraight, as illustrated by way of example in the figures, or they maybe shaped in different ways. The absorbent body 12 comprises a fronttransverse side 16 and a rear transverse side 18. The absorbent body 12also comprises two front oblique sides 20 and two rear oblique sides 22.The two front oblique sides 20 and the two rear oblique sides 22 may besymmetrical with respect to the longitudinal axis A. Each of the obliquesides 20, 22 connects one end of the respective front transverse side 16or the respective rear transverse side 18 to a corresponding end of therespective longitudinal side 14.

The absorbent body 12 may comprise an absorbent core 26, which may besandwiched between an inner sheet of liquid-permeable material(topsheet) and an outer sheet of impermeable material (backsheet).Additional absorbent layers may be comprised between the inner sheet andthe outer sheet of the absorbent body 12 such as, for example, anAcquisition Diffusion Layer of the liquids, commonly referred to as ADL.The inner sheet or topsheet of the absorbent body 12 has a surfaceintended to face, during use, towards the user's body. The absorbentbody 12 may comprise additional components (not illustrated) as iscustomary in the field, such as, for example, elastic elements for thelegs (leg cuffs) applied onto the inner sheet and extending parallellyto the longitudinal axis A.

The absorbent sanitary article 10 comprises two elastic waistbands 28located on opposite sides of the longitudinal axis A. Each of the twoelastic waistbands 28 has two longitudinal sides 30 which, in theextended position of FIG. 1 , extend in the direction of thelongitudinal axis A. Each of the two elastic waistbands 28 has a frontoblique side overlapping and fixed to the corresponding front obliqueside 20 of the absorbent body 12, and an overlapping rear oblique sidefixed to a corresponding rear oblique side 22 of the absorbent body 12.In the extended configuration of FIG. 1 , each elastic waistband 28extends in the direction of the longitudinal axis A between a frontoblique side 20 and a corresponding rear oblique side 22 and overlaps ona corresponding side strip of the absorbent body 12. In a possibleembodiment, the outer longitudinal sides 30 of the elastic waistbands 28may be aligned with the longitudinal sides 14 of the absorbent body 12.

At least one of the two elastic waistbands 28 includes a front section28′ and a rear section 28″ separated from each other by a transverse cutindicated by 32 in FIG. 1 .

The front section 28′ and the rear section 28″ of at least one of thetwo elastic bands 28 are joined together by refastenable closureformations 34, 36. The refastenable closure formations 34, 36 are fixedto respective sections 28′, 28″ of the respective elastic band 28. Afirst closure formation 34 extends on the surface of a single section28′ and the second closure formation 36 extends over the transverse cut32. The closure formations 34, 36 may comprise adhesive, or“hook-and-loop” mechanical attachment means, or their combinations. In apossible embodiment, the closure formation 34 applied on the frontsection 28′ may be a closure formation of the loop type and the closureformation 36 fixed to the rear section 28″ may be a closure formation ofthe hook type. The closure formations 34, 36 of each elastic band 28,when coupled together, establish the continuity of each elastic band 28through the transverse cut 32.

In a possible embodiment, each of the elastic waistbands 28 comprises arespective front section 28′ and a respective rear section 28″ separatedfrom each other by a transverse cut 32 and joined together byrefastenable closure formations 34, 36.

When the closure formations 34, 36 are coupled together, the absorbentsanitary article 10 has a closed pant-like conformation, and the elasticwaistbands 28 form part of the waistband of the garment. The closureformations 34, 36 may be separated from each other to allow opening ofthe absorbent sanitary article 10 along the elastic waistbands 28, asillustrated in FIGS. 2 and 3 .

According to a possible embodiment, the closure formations 34, 36 arefixed on non-elastic end portions of the respective sections 28′, 28″.The closure formations 32, 34 may be fixed to the respective sections28′, 28″ of the elastic bands 28 by glue or, alternatively, by welding.With reference to FIGS. 4-17 , a possible embodiment of a method and anapparatus for producing an absorbent sanitary article 10 of the typeillustrated in FIGS. 1-3 will now be described.

The method involves forming two elastic bands having an indefiniteextension in the longitudinal direction in the unit illustrated in FIG.4 , and applying the elastic bands onto a continuous absorbent compositeweb in the unit illustrated in FIG. 11 .

The operations and units for forming the elastic bands and theoperations and units for applying the elastic bands onto a continuousabsorbent composite web will be described separately below.

With reference to FIG. 4 , numeral 38 indicates—in its entirety—anelastic band forming unit. A plurality of parallel elastic threads 40are fed—in a tensioned state—in a longitudinal direction, in thedirection indicated by the arrow B. A glue applicator 42 intermittentlyapplies transverse strips of glue onto the elastic threads 40, saidstrips indicated by 44 in FIG. 5 , spaced apart in the longitudinaldirection of the elastic threads 40. The elastic threads 40 are enclosedbetween two non-elastic sheets 46, 48, for example, of non-woven fabric,so as to form a continuous elastic band 50 (FIG. 5 ). A pair of pressurerollers 52 presses the non-elastic sheets 46, 48 and the elastic threads40 together. The elastic threads 40 are fixed to the non-elastic sheets46, 48 along the transverse strips 44 on which the glue has beenapplied.

With reference to FIGS. 4 and 6 , the continuous elastic band50—downstream of the pressure rollers 52—is cut in the longitudinaldirection, by a longitudinal cutting unit 54, so as to give rise to twoelastic bands 56. A spacer unit 57 envisages the spacing apart of thetwo elastic bands 56 in a transverse direction, and arranging the twoelastic bands 56 parallel to each other and at a predetermined distance.The elastic bands 56 spaced from each other in the transverse directionare fed onto the outer surface of a wheel 58 rotatable in the directionindicated by the arrow C.

With reference to FIGS. 4 and 7 , a first cutting device 60 cooperateswith the outer surface of the wheel 58, and carries out the transversecutting of the elastic threads 40 of the two elastic bands 56 at regularintervals. The transverse cutting of the elastic threads 40 isschematically indicated by 62 in FIG. 7 , and is located in anintermediate position between two adjacent strips of glue 44. In apossible embodiment, the cutting device 60 may be configured totransversely cut only the elastic threads 40, without cutting thenon-elastic sheets 46, 48. With reference to FIG. 7 , following thetransverse cutting of the elastic threads 40 along the transverse lines62, the elastic threads 40 retract in the longitudinal direction up tothe transverse fastening lines 44 adjacent to the cutting lines 62, thusforming non-elastic areas 64 on each of the elastic bands 56. Thenon-elastic areas 64 of each elastic band 56 are spaced apart at regularintervals in the longitudinal direction. Each of the non-elastic areas64 is comprised between two transverse fastening lines 44 adjacent tothe cutting line 62 of the elastic bands.

With reference to FIG. 4 , the elastic band forming unit 38 comprises afirst closure formation applying unit 65 and a second closure formationapplying unit 67, which both cooperate with the wheel 58. The firstclosure formation applying unit 65 is located immediately downstream ofthe cutting device 60 of the elastic bands. A second cutting device 66configured to carry out the transverse cutting of the elastic bands 56,at regular intervals, is arranged between the first closure formationapplying unit 65 and the second closure formations applying unit 67.

Each of the two closure formation applying units 65, comprises anapplicator roller 68 cooperating with a cutting roller 70, a glueapplicator 72, and a web material feeder 74 configured to feed twocontinuous webs 76, 78 to the applicator roller 68, from whichsuccessive pairs of first closure formations 34 and second closureformations 36 are cut.

With reference to FIGS. 4 and 8 , the first closure formation applyingunit 65 applies first closure formations 34 onto the elastic bands 56,which may be fixed onto the elastic bands 56 by the glue applied by theglue applicator 72. The first closure formations 34 may be applied ontothe non-elastic areas 64, and may occupy only a part of the respectivenon-elastic areas 64.

With reference to FIGS. 4 and 9 , the transverse cutting unit 66 makestransverse cuts 32 on the elastic bands 56, which extend through thenon-elastic areas 64 and are adjacent to the first closure formations34. Following the transverse cuts 32, the elastic bands 56 are dividedinto a succession of elastic sections separated from each other.

With reference to FIGS. 4 and 10 , after executing the transverse cuts32, the second closure formation applying unit 67 applies the secondclosure formations 36 onto the elastic bands 56. The second closureformations 36 may be applied on respective non-elastic areas 64. Thesecond closure formations 36 may be attached by a layer of glue appliedby the glue applicator 72. Each of the second closure formations 36extends over a respective transverse cut 32, and is engaged in thecorresponding first closure formation 34. The second closure formations36 re-establish the continuity of the elastic sections separated fromeach other by the transverse cuts 32.

Downstream of the second closure formation applying unit 67 the twoelastic bands 56 having the shape illustrated in FIG. 10 are detachedfrom the surface of the wheel 58 and are fed to an elastic band applyingunit, indicated—in its entirety—by 80 in FIG. 11 .

With reference to FIGS. 11 and 12 , the elastic band applying unit 80comprises a conveyor 82 that advances a continuous absorbent compositeweb 84 in the direction D. With reference to FIG. 12 , the continuousabsorbent composite web 84 may comprise a plurality of absorbent cores26 oriented parallelly to the longitudinal direction A of the continuousabsorbent composite web 84 and sandwiched between a topsheet and abacksheet. The conveyor 82 feeds the continuous absorbent composite web84 onto the surface of a wheel 86 that is rotatable in the directionindicated by the arrow E.

With reference to FIGS. 11 and 13 , the two elastic bands 56 coming fromthe elastic band forming unit 38 are fed onto the surface of the wheel86. With reference to FIGS. 11 and 14 , the elastic bands 56 are appliedonto the continuous absorbent composite web 84 as it advances on thesurface of the wheel 86, and are overlapped on respective side portionsof the continuous composite web 84. The elastic bands 56 are arranged ina predetermined phase relationship with respect to the continuousabsorbent composite web 84.

With reference to FIGS. 11 and 15 , the elastic band applying unit 80comprises a welding unit 88, which is configured to attach the elasticbands 56 to the continuous absorbent composite web 84 along junctionlines 90. The junction lines 90 are inclined with respect to thelongitudinal axis A. The junction lines 90 may be straight or entirelyor partly curved. In a possible embodiment, the junction lines may havea V shape open outwards. With reference to FIG. 15 , the junction lines90 may be located in an intermediate position between successive pairsof closure formations 34, 36. The junction lines 90 may be symmetricalwith respect to a transverse line which is arranged between twosuccessive absorbent cores 26 of the continuous absorbent composite web84.

With reference to FIGS. 11 and 16 , the elastic band applying unit 80comprises a cutting device 92 cooperating with the wheel 86, andconfigured to cut the continuous absorbent composite web 84 and theelastic bands 56 along cutting lines at regular intervals 94. In apossible embodiment, the cutting lines 94 may have a double Y shape. Thecutting lines 94 may have V-shaped oblique sections that may be flushwith the junction lines 90 and transverse sections that join togetherthe vertices of the V-shaped sections. The cutting lines divide thecontinuous absorbent composite web 84 and the elastic bands 56 into asuccession of absorbent sanitary articles 10 (FIG. 17 ), each having thestructure previously described with reference to FIG. 1 . The absorbentsanitary articles 10 are detached from the surface of the wheel 86 by arelease roller 96, and are deposited on an outlet conveyor 98. Thedouble Y-shaped cutting lines 94 form triangular-shaped scraps 100 (FIG.16 ), which are retained by suction on the surface of the wheel 86 andare removed and discarded into a scrap collection channel indicatedschematically by 102 in FIG. 11 . The double Y-shaped cutting lines 94divide the continuous elastic bands 56 into a succession of discreteelastic waistbands 28, each of which is formed by two elastic sections28′, 28″ separated from each other by the transverse cuts 32, and joinedtogether by the refastenable closure formations 34, 36.

Of course, without prejudice to the principle of the invention, thedetails of construction and the embodiments can be widely varied withrespect to those described and illustrated, without thereby departingfrom the scope of the invention as defined by the claims that follow.

The invention claimed is:
 1. A method for producing absorbent sanitaryarticles, comprising: providing a continuous absorbent composite webhaving a longitudinal axis, advancing said continuous absorbentcomposite web in a direction of said longitudinal axis, forming twoelastic bands having an indefinite extension in a longitudinaldirection, at least one of which comprises a succession of elasticsections separated from each other by transverse cuts and joinedtogether by refastenable closure formations, overlapping said elasticbands on respective side portions of the continuous absorbent compositeweb, fixing the elastic bands to the continuous absorbent composite webalong junction lines inclined with respect to the longitudinal axis, andcutting the continuous absorbent composite web and the elastic bandsalong cutting lines, so as to give rise to a succession of absorbentsanitary articles each having an absorbent body elongated in thelongitudinal direction, having two front oblique sides and two rearoblique sides, and two elastic waistbands fixed to the absorbent bodyalong said front and rear oblique sides, wherein at least one elasticwaistband has a front section and a rear section separated from eachother by a transverse cut and joined together by refastenable closureformations.
 2. The method according to claim 1, comprising: formingnon-elastic areas on at least one of said elastic bands, fixing firstclosure formations of the closure formations to said non-elastic areas,transversely cutting said elastic bands through said non-elastic areas,and fixing second closure formations of the closure formations to saidnon-elastic areas, said second closure formations extending at saidtransverse cuts and engaging said first closure formations in arefastenable manner.
 3. The method according to claim 1, wherein each ofsaid elastic waistbands has a respective front section and a respectiverear section separated from each other by a transverse cut and joinedtogether by the refastenable closure formations.
 4. The method accordingto claim 1, wherein said junction lines inclined with respect to thelongitudinal axis have a V-shape opening outwards.
 5. The methodaccording to claim 2, wherein the step of forming non-elastic areas onsaid elastic bands is carried out by a transverse cut of longitudinalelastic threads of said elastic bands.
 6. An apparatus for producingabsorbent sanitary articles, comprising: a conveyor configured toadvance a continuous absorbent composite web in a longitudinaldirection, the continuous absorbent composite web having a longitudinalaxis, an elastic band forming unit configured to form two elastic bandshaving an indefinite extension in the longitudinal direction, at leastone of which comprises a succession of elastic sections separated fromeach other by transverse cuts, and joined together by refastenableclosure formations, an elastic band application unit configured tooverlap said elastic bands to respective side portions of the continuousabsorbent composite web, and to fix the elastic bands to the continuousabsorbent composite web along junction lines that are inclined withrespect to the longitudinal axis, a cutting device configured to cut thecontinuous absorbent composite web and the elastic bands along cuttinglines so as to give rise to a continuous succession of absorbentsanitary articles each having an absorbent body elongated in thelongitudinal direction and having two front oblique sides and two rearoblique sides, and two elastic waistbands elongated in said longitudinaldirection and fixed to the absorbent body along said front oblique sidesand along said rear oblique sides, wherein each elastic band has a frontsection and a rear section separated from each other by a transverse cutand joined together by refastenable closure formations.
 7. The apparatusaccording to claim 6, wherein said elastic band forming unit comprises afirst cutting device configured to transversely cut longitudinal elasticthreads of said continuous elastic bands.